List of relevant papers:
Grabowski TB, Thorsteinsson V, McAdam BJ, Marteinsdóttir G. 2011. Evidence of Segregated Spawning in a Single Marine Fish Stock: Sympatric Divergence of Ecotypes in Icelandic Cod? PLoS One. 6(3):1–9. Relevance: This paper describes a potential mechanism for the reproductive isolation of the different cod morphs and lays a foundation for one of the NorMER student project.
Jakobsdottir KB, Pardoe H, Magnússon Á, Björnsson H, Pampoulie C, Ruzzante DE, Marteinsdóttir G. 2011. Historical changes in genotypic frequencies at the Pantophysin locus in Atlantic cod (Gadus morhua) in Icelandic waters: evidence of fisheries-induced selection? Evolutionary Applications. 4:562–573. Relevance: This paper describes some of the life history differences between the different cod morphs and lays a foundation for one of the NorMER student project.
Jonsen ID, Basson M, Bestley S, Bravington MV, Patterson TA, Pedersen MW, Thomson R, Thygesen UH, Wotherspoon SJ. 2012. State-space models for bio-loggers: A methodological road map. Deep-Sea Res. II. http://dx.doi.org/10.1016/j.dsr2.2012.07.008 Relevance: Provides a stronger approach for extracting key information about foraging, migration, and other behaviours from animal tracking data, such as can be used to monitor cod.
Jørgensen C, Holt RE. 2012. Natural mortality: its ecology, how it shapes fish life histories, and why it may be increased by fishing. Journal of Sea Research. 75:8–18. doi:10.1016/j.seares.2012.04.003 Relevance: The paper illustrates how a stronger focus on natural mortality may be required to better understand contemporary changes in fish life histories and behaviour and their responses to anthropogenic drivers. By focusing on classes of mechanisms underlying natural mortality, instead of particular traits, it can help broaden the perspective on how species might respond to anthropogenic and natural drivers in the seas.
McAdam BJ, Grabowski TB, Marteinsdóttir G. 2012. Testing for differences in spatial distributions from individual based data. Fisheries Research. 127–128:148–153. Relevance: A statistical method developed to analyse data used in the NorMER project.
McAdam BJ, Grabowski TB, Marteinsdóttir G. 2012. Identification of stock subunits using morphological markers. J Fish Biol. 81(5):1447–1462. http://onlinelibrary.wiley.com/doi/10.1111/j.1095-8649.2012.03384.x/abstract Relevance: A method based on body morphology was developed to discriminate between the different cod morphs. This method is one of the three methods used to classify cod in one of the NorMER student projects.
Opdal AF, Vikebø F, Fiksen Ø. 2011. Parental migration, climate and thermal exposure of larvae: spawning in southern regions gives Northeast Arctic cod a warm start. Marine Ecology Progress Series. 439:255–262. Relevance: The NEA cod population migrates southwards along the Norwegian coast to spawn every year. Over the last century the spawning grounds further south have been abandoned, resulting in a much lower overall temperature exposure for eggs and larvae. Here we have used general circulation models to quantify this effect, and the results show that the temperature exposure of early life stages are more sensitive to variability in spawning ground usage than to climatic variability.
Pampoulie C, Danielsdottir AK, Thorsteinsson V, Hjorleifsson E, Marteinsdóttir G, Ruzzante DE. 2012. The composition of adult overwintering and juvenile aggregations of Atlantic cod (Gadus morhua L.) around Iceland using neutral and functional markers: a statistical challenge. Can. J. Fish. Aquat. Sci. 69:1–14. Relevance: This paper deals with populations structure of cod and lays a foundation for one of the NorMER student project.
Utne K, Huse G, Ottersen G, Holst J, Zabavnikov V, Jackobsen J, Oskarsson G, Nøttestad L. 2012. Horizontal distribution and overlap of planktivorous fish stocks in the Norwegian Sea during summers 1995–2006. Marine Biology Research. 8:420–441. Relevance: Here the spatial overlap between large ecologically and commercially important pelagic fish species in the Norwegian sea is examined and reasons for temporal variability in overlap discussed. The role of processes involving competition and other inter-species interaction is of interest will beyond this one ecosystem.
Therkildsen NO, Hemmer-Hansen J, Hedeholm RB, Wisz MS, Pampoulie C, Meldrup D, Bonanomi S, Retzel A, Olsen SM, Nielsen EE. 2013. Spatiotemporal SNP analysis reveals pronounced biocomplexity at the northern range margin of Atlantic cod Gadus morhua. Evolutionary Applications. 6:690–705. Relevance: Provides one of the first spatiotemporal population genomics studies on wild populations published for any species. The study identified the complex and dynamic interactions of four genetically distinct group of cod inhabiting the northern range margin of the species.
Nielsen B, Hüssy K, Neuenfeldt S, Tomkiewicz J, Behrens JW, Andersen KH. 2013. Individual behaviour of Baltic cod Gadus morhua in relation to sex and reproductive state. doi:10.3354/ab00505 Aquatic Biology. Relevance: Male cod migrate earlier to spawning ground than female cod.
Brander K, Neuheimer A, Andersen KH, Hartvig M. 2013. Food for Thought: Overconfidence in model projections. ICES Journal of Marine Science. 70(6):1065–1068. Relevance: Comment on recent ‘physiologically based’ projections of climate change on the global distribution of fish stocks.
Bárðarson H, McAdam BJ, Petursdottir G, Marteinsdóttir G. 2014. To glue or not to glue? Reassembling broken otoliths for population discrimination. Journal of Fish Biology doi: 10.1111/jfb.12390. Relevance: This study demonstrates that G. morhua otoliths that have been broken for age determination can in most cases be glued back together and applied in morphological analyses. Otolith morphology could then be applied for studies detailing the drivers, patterns and trend of cod populations by applying the method on archived otolith collections.
Möllmann C, Lindegren M, Blenckner T, Bergström L, Casini M, Diekmann R, Flinkman J, Müller-Karulis B, Neuenfeldt S, Schmidt JO, Tomczak M, Voss R, Gårdmark A. 2013. Implementing ecosystem-based fisheries management: from single species to integrated ecosystem assessment and advice for Baltic Sea fish stocks. ICES Journal of Marine Science. doi:10.1093/icesjms/fst123 Relevance: We combine tactical and strategic management aspects into a single strategy that supports the present Baltic Sea fish stock advice. We first review the state of the art in the development of integrated ecosystem assessments (IEAs) and then outline and discuss an approach that integrates fish stock advice and IEAs for the Baltic Sea
Ohlberger J, Rogers LA, Stenseth NC. 2014. Stochasticity and determinism: How density-independent and density-dependent processes affect population variability. PlosOne DOI: 10.1371/journal.pone.0098940 Relevance: We find evidence of strong density dependence in juvenile survival, which dampens the impact of stochasticity operating earlier in life such as climatic impacts on the productionof eggs and larval survival. Our results highlight that the timing of density dependence in demographic rates determines how stochastic processes translate into patterns of population variability.
Durant JM, Hidalgo M, Rouyer TA, Hjermann D, Ciannelli L, Eikeset AM, Yaragina NA, Stenseth NC. 2013. Population growth across heterogeneous environments: effects of harvesting and age structure. Marine Ecology — Progress Series. ISSN 0171-8630. 480:277–287. doi:10.3354/meps10308 Relevance: This study illustrates how and where the interaction between large-scale ecological patterns and regional/short-scale processes are important for designing management regulations.
Ottersen G, Stige LC, Durant JM, Chan K-S, Rouyer TA,
Drinkwater KF, Stenseth NC. 2013. Temporal shifts in recruitment dynamics of North Atlantic fish stocks: effects of spawning stock and temperature. Marine Ecology — Progress Series. ISSN 0171-8630. 480:205–225. doi:10.3354/meps10249 Relevance: Effects of variation in spawning stock and sea temper- ature on long-term temporal patterns in recruitment dynamics of 38 commercially harvested fish stocks in the northern North Atlantic were studied. Threshold models performed better than the best linear or nonlinear stationary models for 27 of the stocks, suggesting that abrupt changes (maybe even regime shifts) are common.
Durant JM, Hjermann D, Falkenhaug T, Gifford D, Naustvoll LJ, Sullivan B, Beaugrand G, Stenseth NC. 2013. Extension of the match- mismatch hypothesis to predator-controlled systems. Marine Ecology Progress Series. ISSN 0171-8630. 474:43–52. doi:10.3354/meps10089 Relevance: We suggest that an increase in asynchrony between predator and prey peak abundance can lead to increased survival and potentially increased recruitment of the prey in some system.
Hidalgo M, Rouyer TA, Bartolino V, Cerviño S, Ciannelli L, Massuti E, Jadaud A, Saborido-Rey F, Durant JM, Santurtun M, Piñeiro CG, Stenseth NC. 2012. Context-dependent interplays between truncated demographies and climate variation shape the population growth rate of a harvested species. Ecography. ISSN 0906-7590. 35(7):637–649. doi:10.1111/j.1600 0587.2011.07314.x Relevance: Our study shows that the interaction between internal characteristics and external forces changes across geographic locations according to 1) the importance of demographic truncation, 2) the influence of the climate on the regional hydrography and 3) the spatiotemporal heterogeneity of the physical environment to which fish life history is adapted.
Neuenfeldt S, Righton D, Neat F, Wright PJ, Svedang H, Michalsen K, Subbey S, Steingrund P, Thorsteinsson V, Pampoulie C, Andersen KH, Pedersen MW, Metcalfe J. 2013. Analysing migrations of Atlantic cod Gadus morhua in the north-east Atlantic Ocean: then, now and the future. Journal of Fish Biology. Relevance: The application of data storage tags bears the potential for a quantum leap in the research on fish migrations, because not only first-capture and recapture positions are known, but at least theoretically, the migration path during the period at large can be reconstructed. Besides presenting the state-of-the-art geolocations for cod Gadus morhua in the north-east Atlantic Ocean, the major aim of this review is to raise awareness of gaps in knowledge and to identify ideas for new research.
Jonsen ID, Basson M, Bestley S, Bravington MV, Patterson TA, Pedersen MW, Thomson R, Thygesen UH, Wotherspoon SJ. 2012. State-space models for bio-loggers : A methodological road map. Deep Sea Research Part II: Topical Studies in Oceanography. Relevance: Despite the widespread utility, and current popularity, of state-space models for analysis of animal tracking data, these tools are not simple and require considerable care in their use. Here we develop a methodological ‘road map’ for ecologists by reviewing currently available state-space implementations.
Baktoft H, Aarestrup K, Berg S, Boel M, Jacobsen L, Koed A, Pedersen MW, Svendsen JC, Skov C. 2013. Effects of angling and manual handling on pike behavior investigated by high resolution positional telemetry. Fisheries Management and Ecology. Relevance: Results demonstrated that the handling protocol caused temperature-dependent changes in pike activity, with higher temperatures leading to lower activity of the recaptured pike. The effects, however, were transitory and not detectable after 48-h post- release. These findings indicate that pike are relatively resilient to handling and quickly resume pre-handling activity.
Hutniczak B, Nieminen E, Hoffmann J, & Yletynen J. Input-efficiency of fishing cod in the Baltic sea – comparing major EU trawler fleets. University of Helsinki. Departmenrt of Ecomonics and Management. Discussion Papers n:o 68. Helsinki 2015. Relevance: EU regulations strive for cooperative decisions, instead of regular ‘race-to-fish’, to safeguard a good biological state for a fish stock. However, asymmetries between fishing countries may translate into different access to the common pool resource. This study addresses a potential shortcoming of the vast literature on fishery resource exploitation, namely the assumption about the uniformly distributed effort, and provides preliminary research regarding the potential flow of individual Baltic Sea cod quotas between countries in case the quota market would be open for free trade.
Blenckner T, Llope M, Möllmann C, Voss R, Quaas MF, Casini M, Lindegren M, Folke C, Stenseth NC. 2015. Climate and fishing steer ecosystem regeneration to uncertain economic futures. Proceedings of the Royal Society of London B: Biological Sciences, 282(1803). Relevance: By applying a statistical food web model, using the Baltic Sea as a case study, we show that under current temperature and salinity conditions, complete recovery of this heavily altered ecosystem will be impossible. We think that this study is relevant to managers and policy makers by providing a new perspective to the potential bioeconomics of the Baltic Sea. Our results point out that: (1) the regeneration of an ecosystem to an economic target is not straightforward, as there are multiple interacting drivers involved that need be considered and understood, and (2) an accurate evaluation of a given management strategy should account for these drivers and incorporate non linear and regime dependent dynamics, as these features have been observed and determine the final outcome.
Bonanomi S, Therkildsen NO, Hedeholm RB, Hemmer-Hansen J, Nielsen EE. 2014. The use of archived tags in retrospective genetic analysis of fish. Molecular Ecology Resources, 14(3), 616–21. doi:10.1111/1755-0998.12211 Relevance: This manuscript describes a new method for the extraction of DNA from historical fish tags. Of particular note, in this study the direct behavioral information provided by the tag gives an extra dimension by allowing direct comparisons of changes in spatial dynamics (e.g. migration patterns) with the genetic information at the level of individual fish.